function z=f(x,y)
sigma = 1.25;
z=(1/(2*%pi*sigma)*exp(-((x^2+y^2)/(2*sigma))))
endfunction


clf()

x=linspace(-3,3,64);
y=linspace(-3,3,64);
z=feval(x,y,f);

set(gcf(),"color_map",[graycolormap(64)]);

drawlater();

subplot(1,2,1)
mesh(x,y,z)
subplot(1,2,2)
Sfgrayplot(x,y,f)

drawnow();

show_window()
